import java.util.LinkedList;

public class Main {
    public static void main(String[] args) {
        LinkedList<Integer> list=new LinkedList<>();
        list.addLast(1);
        list.addLast(2);
        list.addLast(3);
        System.out.println(list);
        list.add(2,6);
        System.out.println(list);
    }
}